Reflective element assemblies for exterior rearview mirror assemblies of vehicles may include a heater pad disposed at the rear of the mirror reflective element to limit icing or fogging of the mirror reflective element. Examples of known heater pads are described in U.S. Pat. Nos. 8,058,977; 7,400,435 and 5,808,777, which are hereby incorporated herein by reference in their entireties. For applications where the mirror assembly comprises an electrochromic reflective element and/or a blind zone indicator or the like, each electrical function of the mirror assembly or reflective element assembly (such as the heater pad, EC control, blind zone indicator and the like) is electrically connected to a respective wiring harness of the mirror assembly.